I heard that more and more studies are showing that back belts don't really protect the back and may even weaken it. How is this possible?

Several researchers believe that back belts may lead to muscle weakness because they transfer the load from the back to the abdomen, pelvis, and legs.

Studies have shown that when a back belt is in place, the electrical activity of the back muscles is decreased. This means the muscles are not active or contracting. Over time, this can have a "detraining" effect on the muscles of the back. Once the belt is no longer used, the injury rate goes up. More research is needed to confirm this theory.